signature ratUtils =
sig
        type term = Term.term
        type thm = Thm.thm
        type goal = Abbrev.goal
        type conv = Abbrev.conv
        type tactic = Abbrev.tactic

        val dest_rat : term -> term * term list
        val extract_rat : term -> term list

        val extract_rat_vars : term -> term list
        val extract_rat_equations : term -> term list
        val extract_rat_minv : term -> term list

end
